Math Problem Statement

ACTIVITY #1 - Random variables with discrete and continuous classification problems, including coin tosses, ball draws, and dice rolls.

Solution

Here’s the analysis and solution to the activity:


Part A:

  1. Four coins are tossed (Random variable X represents the number of tails):

    • Possible outcomes for 4 coins are:
      {HHHH, HHHT, HHTH, HTHH, THHH, HHTT, HTHT, TTHH, HTTH, THHT, THTH, TTTH, HTTT, THTT, TTHT, TTTT}.
      • Number of tails (X) in each outcome ranges from 0 to 4.
    • Values of X: {0, 1, 2, 3, 4}
  2. Three balls are drawn without replacement (Random variable Z represents the number of blue balls):

    • The total composition of balls is:
      5 red, 6 yellow, 6 blue (Total = 17 balls).
      • Since three balls are drawn, Z (number of blue balls) can take values:
        {0, 1, 2, 3}.
        The values depend on the combination of draws (e.g., no blue balls drawn, exactly 1 blue ball, etc.).

Part B: Write all possible values of each random variable:

  1. X: Number of odd-number outcomes in a roll of two dice.

    • Possible outcomes for one die: {1, 2, 3, 4, 5, 6}.
      Odd outcomes: {1, 3, 5}.
      • For two dice, the number of odd outcomes can range from 0 (no dice showing odd) to 2 (both dice showing odd).
        Values of X: {0, 1, 2}.
  2. Z: Scores of a student in a 15-item test.

    • Possible scores range from 0 (no correct answers) to 15 (all correct).
      Values of Z: {0, 1, 2, ..., 15}.
  3. Y: Height (in ft) of a basketball player not exceeding 7 ft.

    • Heights can vary continuously between a lower bound and 7 ft.
      Values of Y: Any real number in the interval [0, 7] (continuous variable).
  4. W: Product of two numbers taken from two boxes containing numbers 1 to 6.

    • Possible products are the results of multiplying any pair of numbers from {1, 2, 3, 4, 5, 6}.
      Products: {1, 2, 3, 4, 5, 6, 4, 6, 8, 9, 10, 12, ..., 36} (all unique combinations).
      Values of W: {1, 2, 3, 4, 5, 6, 8, 9, 10, 12, ..., 36}.

Part C: Classify each random variable as discrete or continuous:

  1. Score of a student in a quiz:

    • Discrete (Scores are countable integers).
  2. How long students ate breakfast:

    • Continuous (Time is measured, not counted).

Follow-up Questions:

  1. How would the probabilities be calculated for X in part A1?
  2. Can Z in part A2 change if the composition of balls changes?
  3. What is the maximum possible value for W in part B4?
  4. How do you classify other variables not explicitly mentioned as discrete or continuous?
  5. What are the practical implications of distinguishing discrete and continuous variables?

Tip:

When analyzing random variables, always check the nature of their outcomes: countable (discrete) or measurable on a continuous scale (continuous).

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Probability
Random Variables
Discrete Variables
Continuous Variables

Formulas

Binomial probability for coin tosses
Combinatorial outcomes for draws without replacement

Theorems

Concept of Random Variables
Discrete vs Continuous Variable Classification

Suitable Grade Level

Grades 9-11